Green Potatoes Are They Poisonous?

Holistic Nutrition

You must have heard your mom say that green potatoes are bad and you cannot use them, rather toss them in the bin. Then other people will just cut the green parts off the potato. Either way, green potatoes are not more desirable than the normal brown colored ones. Mostly since, they are seen as dangerous.

Green potatoes have a bitter taste. The problem is that these green potatoes can develop a toxin.

This article aims to look at if green potatoes are safe to eat or will they make you sick – a full focus on your health.

But this is why potatoes turn green

It is a natural process of potatoes turning green. This happens when they are exposed to light. During this process chlorophyll, the same green pigment found in algae and plants that give them their color, starts to develop.

As the potato changes from a yellow-brownish color to a more greenish color, it might be difficult to notice on darker-skinned potatoes. However, if you scratch off parts of the skin you will notice the green patches underneath the skin. Light-skinned potatoes will not be as difficult as you will notice the green color on skin itself.

Chlorophyll is what gives plants the ability to harvest energy from the sun via the process of photosynthesis. More so, through this process of photosynthesis plants are capable of producing oxygen and carbs from sunlight, carbon dioxide, and water. But in the case of potatoes, chlorophyll which gives that green color could be entirely harmless. In actual fact, it is present in a lot of of the plant foods we eat almost daily.

That all said, there is a problem. The greening of the potatoes can also be a sign of the production of less wanted and harmful compounds called solanine, which is toxic.

Potatoes that are green can be toxic

With the process of chlorophyll, other compounds can be activated. These are to protect the plant from bacteria, fungi, insects and even hungry animals. These compounds can also be toxic to humans.

For instance, solanine is one of these toxins that potatoes produce. This toxin works by inhibiting an enzyme involved in breaking down certain neurotransmitters. However, solanine also acts by damaging cell membranes and can negatively affect your intestine’s permeability. Still, solanine is generally present in low levels in the skin and flesh of potatoes, as well as in higher levels in parts of the potato plant. Yet, when exposed to sunlight or damaged, potatoes produce more of it. A good indicator that the levels of solanine is high is too look out for chlorophyll. Note this is just a hit, not the best of indicators. Although if a potato starts to turn green it is a sign that a potato may be starting to produce more solanine.

When is too much solanine too much?

The point of how much is too much solanine is different to tell and have not been tested on humans for ethical reasons. Then again, factors like body size and individual tolerance might vary.

That said, ingesting 0.9 mg/lb (2 mg/kg) of body weight is enough to cause symptoms, although 0.6 mg/lb (1.25 mg/kg) could be enough to make some people ill. This implies that eating a 450 g potato that has surpassed the acceptable level of 20 mg solanine per 100 g would be enough to make a 50-kg person sick. More problematic, is if a potato has established a very high solanine levels or if the person is smaller or a child, eating this could be enough to make them sick.

The symptoms of solanine poisoning are vomiting, nausea, diarrhea, headaches, sweating, as well as stomach pain. If the poisoning was really bad, then you might experience symptoms like paralysis, breathing problems, convulsions, coma and even death.

What will happen if I peel or boil my green potatoes?

Solanine levels are the most concentrated in the skin of a potato. If you peel a green potato will help reduce its levels a lot. In fact, you can drop the solanine levels by 30 percent. Then again, the flesh could contain the other percentage of 70 percent and you can still get sick.

Different methods of cooking, like boiling, baking, frying, or microwaving the potatoes will not significantly reduce solanine levels or make them safer to consume.

Potato with few small green spots, the spots can be cut off or peeled. That is since the solanine levels are normally on those areas and not very high. But a very green potato should be best thrown away.

Preventing green potatoes

You normally do not buy green potatoes, but if they are handled wrongly potatoes can produce solanine after they have been distributed to a supermarket or while being kept in your kitchen. You should therefore store them correctly to prevent them turning green and solanine developing.

Physical damage, exposure to light and high or even low temperatures are the main factors that encourage potatoes to produce solanine. Make sure to inspect potatoes before buying them to make sure they have not been damaged or already started greening. Then when at home, store your potatoes in a cool, dark place, such as a root cellar or basement. And do keep them away from light.

It is not ideal to store them in the refrigerator as it is too cold. In fact it could increase then solanine levels due to storage at refrigerator temperatures. Then again the average kitchen or pantry is too warm for long-term storage.

If you do not have a cool spot to store your potatoes, only purchase the amount you plan to use. Store them in an opaque bag in the back of a cabinet or drawer, where they will be best protected from light and warmth.

Closing remarks

Green potatoes are problematic. The green color is not the issue, but a good indication that the solanine levels might be too high. This mean that the potatoes could be toxic and harmful, and best not eaten.